Results of an EC laboratory comparison on 40K, 90Sr and 137Cs in dried bilberry powder

•New CRM IRMM-426 Wild Berries was used as test material.•Only 91% and 83% of 137Cs and 40K results within 20% of reference values.•Good performance for 90Sr: 88% within 30% of reference values.•For many labs, discrepant evaluation to En criterion and relative deviations.•Many laboratories cannot estimate realistic uncertainties (137Cs, 90Sr).

The evaluation is presented of a laboratory comparison (LC) on 90Sr, 40K and 137Cs in dried bilberries organised in 2011 by the IRMM. The activity concentrations reported by 88 participant laboratories are compared to the reference values of the new reference material IRMM-426 Wild Berries. Nine per cent and 17% of activity concentration results for 137Cs and 40K, respectively, deviate more than 20% from the reference values, a result worse than that obtained in previous LCs. For 90Sr, about 88% of results lie within 30% of the reference value, better than observed in previous LCs. But only 58% of 90Sr results are satisfactory in terms of the En criterion, indicating difficulties with a complete uncertainty estimation.